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arXiv · 1511.08469

Theoretical Prediction of the Nematic Orbital-Ordered State in Ti-Oxypnictide Superconductor BaTi2(As,Sb)2O

Hironori Nakaoka·Youichi Yamakawa·Hiroshi Kontani
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Abstract

The electronic nematic state without magnetization emerges in various strongly correlated metals such as Fe-based and cuprate superconductors. To understand this universal phenomenon, we focus on the nematic state in Ti-oxypnictide BaTi2(As,Sb)2O, which is expressed as the three-dimensional 10-orbital Hubbard model. The antiferromagnetic fluctuations are caused by the Fermi surface nesting. Interestingly, we find the spin-fluctuation-driven orbital order due to the strong orbital-spin interference, which is described by the Aslamazov-Larkin vertex correction (AL-VC). The predicted intra-unit-cell nematic orbital order is consistent with the recent experimental reports on BaTi2(As,Sb)2O. Thus, the spin-fluctuation-driven orbital order due to the AL-VC mechanism is expected to be universal in various two- and three-dimensional multiorbital metals.

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Hironori Nakaoka, Youichi Yamakawa, Hiroshi Kontani. 2016-05-11. Theoretical Prediction of the Nematic Orbital-Ordered State in Ti-Oxypnictide Superconductor BaTi2(As,Sb)2O. https://doi.org/10.1103/physrevb.93.245122

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